1. Field of the Invention
The present invention relates to a liquid droplet discharge unit for discharging droplets from a nozzle and a liquid droplet discharge apparatus provided with the droplet discharge unit.
2. Description of the Related Art
In a liquid droplet discharge unit such as an ink jet recording head unit which discharges ink droplets from a nozzle onto a sheet, a drive section such as a piezoelectric actuator changes the volume of a pressure chamber to cause liquid filled in the pressure chamber to be discharged as droplets from a nozzle which is communicated with the pressure chamber. Since these drive sections are provided corresponding to each pressure chamber, in a case of an elongated droplet discharge head whose width is equal to or larger than that of a sheet, the number thereof becomes extremely large. Meanwhile, with recent demands to increase print speeds, the driving speed of the drive sections has been speeded up. Thus, the amount of heat of a drive element which transmits an electrical signal to the drive sections to drive the drive sections increases so that damage of the drive element by heat occurs easily. Because of this, various methods for quickly radiating heat away from the drive element have been devised in order to improve the reliability of the drive element (for example, see Japanese Patent Application Laid-Open No. 2003-311953). Various methods for quickly radiating away heat of a liquid droplet discharge head itself also have been devised (for example, see Japanese Patent Nos. 2723998 and 2732693).
Here, in the case of the elongated droplet discharge head, since it is difficult, in terms of mounting, to electrically connect plural drive sections with one drive element, the plural drive sections are divided into a plurality of portions, and one drive element is provided for each portion. Thus, as differences in the liquid droplet discharge amounts of the respective portions occur, so differences in the drive amounts of the respective portions occur, whereby differences in the amount of heat of the respective drive elements occur. Thus, there is a problem that differences in reliabilities of the respective drive elements occur.